(717d) Effect of Temperature and Heating Rate on Heel Build-up during Microwave Regeneration
This study investigates the effect of regeneration temperature and heating rate on irreversible
adsorption of organic vapors typically emitted from automotive painting booths. Two types of beaded
activated carbons (BAC), with different porosities (microporous versus mesoporous) were loaded with
1, 2, 4-trimethylbenzene and regenerated at two regeneration temperatures (288 and 400 oC) and at
different heating rates (25, 50, 100, and 150 oC/min). The results showed that for the higher
regeneration temperature (400 oC), increasing heating rate increased heel build-up by as much as 105%
and 189% for the microporous and mesoporous BACs, respectively. The elevated heel formation at
higher heating rates could be due to adsorbate coking as a result of exposure to high temperature.
Conversely, for the lower regeneration temperature (288 oC), increasing the heating rate did not
significantly affect the amount of heel build-up (< 15% and < 5% increase for microporous and
mesoporous BACs, respectively). This could be because the lower regeneration temperature provided
insufficient conditions for coking. The results from this study indicate that the heating rate during
desorption could be optimized to allow fast desorption with minimal adsorbate decomposition.